1. Field of the Invention
The present invention relates to a phytase which has at least 74% identity to a phytase derived from Citrobacter braakii ATCC 51113 and comprises at least one alteration as compared to this phytase (i.e., is a variant thereof). The invention also relates to DNA encoding these phytases, methods of their production, as well as the use thereof, e.g. in animal feed and animal feed additives. The mature part of the Citrobacter braakii ATCC 51113 phytase is included in the sequence listing as SEQ ID NO: 2.
2. Background Art
The sequence of the phyA gene from Citrobacter freundii has been submitted by Zinin et al to the EMBL/GenBank/DDBJ databases with accession no. AY390262. The corresponding phytase amino acid sequence is found in the UniProt/TrEMBL databases with accession no. Q676V7. The expected mature part of Q676V7 is included in the present sequence listing as SEQ ID NO: 4.
WO 2004/085638 discloses, as SEQ ID NO: 7, the amino acid sequence of a phytase from Citrobacter braakii YH-15, deposited as KCCM 10427. The mature part of this amino acid sequence is included herein as SEQ ID NO: 3. This sequence is also found in the database Geneseqp with accession no. ADU50737.
WO 2006/037328 discloses the wildtype phytase of Citrobacter braakii ATCC 51113 (i.e., SEQ ID NO: 2 herein), as well as a variant thereof, which is also included in the present sequence listing, viz. as SEQ ID NO: 6.
WO 2006/038062 and WO 2006/038128 both disclose the amino acid sequence of the phytase gene of Citrobacter freundii P3-42, deposited under accession number NCIMB 41247. This amino acid sequence is included herein as SEQ ID NO: 9.
It is an object of the invention to provide phytases of amended, preferably, improved properties. Non-limiting examples of such properties are: Thermostability, temperature profile pH profile, specific activity, performance in animal feed, protease-sensibility, and/or glycosylation pattern.